System and method for activity monitoring using video data

ABSTRACT

Embodiments of a method and system described herein enable capture of video data streams from multiple, different devices and the processing of the video data streams. The video data streams are merged such that various data protocols can all be processed with the same worker processors on different types of operating systems, which are typically distributed. An embodiment uses a mobile device (such as a mobile phone) as a device and deploys a video sensor application on the mobile device for encoding consecutive video files, time stamping the consecutive video files, and pushing the consecutive video files to a file server to produce a stable stream of video data. Thus avoiding the inefficiencies associated with having video processing in the data flow loop.

RELATED APPLICATIONS

This application claims priority from U.S. Provisional Application No.62/005,815, filed May 30, 2014.

FIELD OF THE INVENTION

Embodiments disclosed herein are in the field of video data processing,in particular object detection and pattern recognition.

BACKGROUND

Various techniques exist for processing digital video data for purposesof image recognition, pattern recognition, object detection, etc.Typically, video data is captured by one type of device and thenanalyzed by the device or by another processing device. For example, onemethod includes acquiring visual image primitives from a video inputcomprising visual information relevant to a human activity. Theprimitives are temporally aligned to an optimally hypothesized sequenceof primitives transformed from a sequence of transactions as a functionof a distance metric between the observed primitive sequence and thetransformed primitive sequence. Another method detects a moving targetwith the use of a reference image and an inspection image from theimages captured by one or more cameras. A moving target is detected fromthe reference image and the inspection image based on the orientation ofcorresponding portions in the reference image and the inspection imagerelative to a location of an epipolar direction common to the referenceimage and the inspection image; and displays any detected moving targeton a display.

Current video data processing techniques typically operate on one typeof video input data. Making available a larger source of data aggregatedfrom multiple sources into a combined source has not been possible forindividual contributors.

In addition, it has proven challenging to process large amounts ofstreaming video data effectively.

It would be desirable to have a system and method for receiving digitalvideo data from multiple sources of different types and be able toanalyze the raw data as a single data source from the different sourcesto determine facts about a scene both at a point in time and over aperiod of time.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an activity monitoring system according toan embodiment.

FIG. 2 is a flow diagram illustrating one video processing algorithmaccording to an embodiment.

FIG. 3 is a flow diagram showing more detail of detection of activityareas from video data according to an embodiment.

FIG. 4 is a flow diagram showing more detail of deriving waiting linesegmentation from video data according to an embodiment.

FIG. 5 is a flow diagram showing more detail of deriving measurements ofattributes from video data according to an embodiment.

FIG. 6 is a diagram illustration of segmentation of a waiting line fromvideo data according to an embodiment.

FIG. 7 is shows a user interface display with a waiting line as capturedby as video camera with currently calculated attributes imposed on theimage.

FIG. 8 is a diagram illustrating as virtual turnstile according to anembodiment.

DETAILED DESCRIPTION

Embodiments described herein include a system and method for processingvideo data from multiple sources in order to determine the status ofvarious aspects of environments. For purposes of illustration and caseof description, the system and methods described will be referred to asthe Placemeter system, or Placemeter. Placemeter uses video streams tomeasure activity levels in the physical world to enable people andbusinesses to interact more effectively and efficiently with physicallocations and cities.

In an embodiment, the Placemeter system uses the input video streamsfrom a variety of sources. Sources include existing video feeds such assecurity cameras, video feeds contributed by system users through oldsmartphones placed in a fixed location simple webcams, or embeddedsensors that contain a video feed and some video analysis software. Thesystem includes a backend subsystem consisting of specially programmedprocessors executing software that manages video feeds, processes thevideo feeds into data, stores the data, and computes analytics andpredictions.

Various novel video algorithms are the part of the system that isdedicated to transforming a video signal into data and measurements.Novel data algorithms combine measurements from video feeds with lowerresolution activity maps or weather information, and local events, toinfer place activity in space and time. An output interface includestools to turn the data extracted from videos into human readableinformation and useful actions.

FIG. 1 is a block diagram of as Placemeter system architecture 100according to an embodiment. Input video sources 102 can include publiccameras, security cameras, mobile application, and any other devicecapable of capturing digital video streams. This includes a proprietaryprotocol to do continuous streaming over long periods of time (which isdifficult in the prior art). A feedback loop is used to reconstruct andidentity (and fix) bandwidth issues.

The input video sources are very varied in nature and quality.Embodiments facilitate the processing and analysis of any possible videosource, whatever its type or support. These sources include: existingpublic video cameras in the form of standard video streams; existingpublic video feeds in the form of jpg files regularly updated on awebsite; simple webcams; security cameras installed for securitypurposes but whose feeds can be ingested by Placemeter to he processedto extract data video streams or files coming from old cell phones thatrun a Placemeter video sensing application. The Placemeter sensing,application can either produce actual video streams, or encore videofiles and push them on a hosted storage server such as FTP server orAmazon S3 server. Using a smartphone as a video sensor enables and easyto set up and configure capture device, that easily streams data outthrough files. This solves a major problem of setting cameras andexporting their feeds to a different network location on the internet.

The system thus provides a unified framework to intake video framescoming from these various described sources, and to unify theirgeolocation and time reference so as to be able to compare anygeolocated or time stamped data extracted from them.

An embodiment uses consecutive video files on the smartphone that areencoded, time stamped, and pushed to an FTP server is an innovative wayto produce as stable stream of video content without having to have avideo streaming server in the loop, but rather a simple file server.Methods disclosed solve many existing problems related to data streamingusing cellphones. Those problems range from fundamental issues likenon-existing protocol, hence no known implementation, to legal issues(e.g. GPL softwares are not allowed to be used on distributed appnetworks like AppStore or Google Apps), and the high expense involved inmaintaining brittle and sophisticated streaming servers sitting betweenthe cellphones and the video algorithm processor.

These video feeds are produced by multiple types of entities, including:companies or entities that own video feeds, and provide them forfree—e.g. the DOT in New York; companies or entities (e.g. retailers)that own video feeds, and provide them to the system in exchange so forhaving them transformed into valuable data companies or organizationsthat are paid for access to the video feeds they own and operate—e.g.earthcam; companies with whom there is no monetary exchange, e.g. theyprovide their feed, in exchange for a minimal amount of data for free;and individual contributors who use old smart phones or contribute oldcell phones, to hang the phones on window or wall surface, and byrunning the Placemeter sensing application on these old phones, they cancreate new Placemeter video feeds. The incentive used to recruit theseindividuals is either monetary or it is based on the value they get fromthe data which Placemeter extracts from their own feeds, or from thePlacemeter network of feeds.

Compiling all these sources to create data insights and analytics hasmore scaling network effect than all single data sources combined. Thisis made possible in part by aggregating data from multiple sources(including individual contributors) into a combined, stable source.

A backend subsystem 104 receives the video data streams from the inputvideo sources 102. Management module 112 is a feed management modulethat receives the video data streams. Other management modules include aworker management module 114, a locations management and geographicintelligence module 116, and a data storage module 118. Data storagemodule 118 is shown as a single module existing in the backend subsystem104. However, actual data storage can be, and typically is, distributedanywhere over the internet. Data storage, module 118 is thus a datamanagement module and possibly actual data storage, but not all datawill be stored locally.

Input video sources 102 also communicate with a contributor manager 110.Contributor manager 110 oversees and tracks the various input videosources, including their locations and “owners”. In some instances,individual owners are paid for making their video data available to thesystem. Video analysis workers 106 represent multiple special purposeprocessors tasked with executing video analysis worker processes asfurther described below. Analyzed video data is stored by data storagemanager 118, and also further analyzed by data analytics 108 as furtherdescribed below. Data analytics 108 represent special purpose processorsexecuting data analytics processes. Data analytics 108 further haveaccess to external data sources 122, which provide data such as weatherinformation, event information related to a location of the video data,etc. Data analytics 108 may combine external data with the output of thevideo analysis workers 106 to produce more meaningful output data thatis stored by data storage manager 118 and output to user interface andapplications 120. User interface and applications 120 make processedvideo data available to users in to highly accessible firm. Userinterface 120 is in various embodiments, available on any computingdevice with processing capability, communication capability, and displaycapability, including personal computers and mobile devices.

In an embodiment, the backend system is a multi-layer system whose rolesinclude: registering all existing video streams and their sources; ifthe source is a contributor, storing availability and contactinformation to provide data or to pay them, based on the availability oftheir sensors; managing “worker” processes that will process all videofeeds in a different subsystem, and will report data to this system;gathering and storing data extracted from video streams; consolidatingand merging all data from various sources (e.g., video measurements,weather APIs); packaging and serving data for application or as anoutput of the system; and architecturally removing the dependency of thevideo algorithm processor on the various sources of data.

According to one aspect of the backend, it serves to coordinate how allinput sources and worker processes are distributed over different typesof networks and environments. An application programming interface (API)is defined for worker processes (worker software processes that can runon any operating system such as Linux, Mac OS or Windows with sufficientRAM and CPU power) to register with the Placemeter backend over a WideArea Network (WAN), assign individual feed with corresponding algorithmparameters and specifications, and then start processing that feed andreporting output data back to the same API endpoint family. These workerprocesses also report on their level of activity, CPU and RAM occupancy,as well as availability. With such a system, Placemeter can instantiateworker processes in many varied environments, thus leveraging availableplatforms that can contribute CPU power.

The system executes various video algorithms and various dataalgorithms. In an embodiment, the video algorithms are based on athree-layer stack. In an embodiment, these three algorithmic layers arebased on the assumption that video feeds have a static viewpoint and anaverage frame rate greater than 0.2 frames per seconds, but embodimentsare not so limited.

Video Algorithms

Moving object detection is a layer is that detects moving objects ormoving parts in the image. It is based on estimating the backgroundimage of a fixed video stream, by modeling each point using a Gaussiandistribution of values on each channel of a color image, or theamplitude of the combined channels. Each pixel is then modeled as:Gaussian distributions for all channels of the color image; a Gaussiandistribution for the pixel luminance expressed as a linear combinationof the three color channels.

Such a model is created and stored in memory for each coordinate pointof an image. As new frames arrive in the system, the Gaussian modelestimation is updated with the new values of each pixel at the samecoordinate by storing the sum S of the pixel values over time, and thesum T of squared values. Given, the total number of observations is N,the average and standard deviation of the Gaussian model can then beevaluated as S/N for the mean value and (2S−S*S)/N for the square valueof the standard deviation.

In order to adjust the Gaussian values to potential changes in the meanand standard deviation, these values are computed on moving timewindows. In order to reduce the complexity of computing all values overa moving averages, a half distance overlapping scheme is used. If M isthe minimum window size (number of samples) over which mean and standarddeviation is to be estimated, two sets of overlapping sums and squaresums are constantly stored: the current sum set and the future sum set.Each set has the number of samples and the sum of values and the sum ofsquare values. When the first set reaches M samples, the second set isreset, and then updated with each new frame. When the first set reachesM*2 samples, the future set reaches M samples. The future set values arethen copied into the current set values, and the future set is reset.This way, at any point in time after M first samples, the estimation ofthe Gaussian model always has more than M samples, and it is adjustedover time windows of M*2 samples. M is typically set to values rangingfrom 10 to 1000 depending on applications and video frame rates.

Once as new frame comes in, for each pixel location in an image, it isfirst assessed whether the current value is part of the background ornot. To do so, the normalized distance of the current pixel values iscomputed for each color channel with the background mean values for eachchannel. The normalized distance is the distance of the current point tothe closest mean adjusted with the standard deviation for the backgroundimages. This distance is then normalized towards the amplitude of eachchannel or the average of all channels. The raw distance calculated fromabove is divided by as uniform factor of the average values.

If this normalized distance is greater than a predefined threshold, thepixel is classified as a foreground pixel and assigned to the movingobjects. If not, the pixel is deemed as part of the background, it isnot assigned to the front end masks but used to update the currentbackground models.

At any point in time, the algorithm assumes that there could be a rapidchange in background, so it maintains a candidate background point. Thatpoint is either updated or created for each point detected as aforeground point.

If the image is too large, the image can be subsampled by an integerfactor to evaluate a lower resolution version of the background. Also,the background statistics can be updated only once every n frames. Thisis very efficient to make the algorithm real time whatever the dimensionor frame rate of a video. The CPU occupancy of such a process iscontrolled and defined with these two parameters. This is a unique wayto linearly adjust algorithm reactivity and accuracy based on availableor desired computation power.

The object classification layer classifies moving foreground objects(described with reference to the previous layer) into classes of knownobjects or “noise”. In one embodiment, as customized version of the HaarPyramid approach is used here. Once all moving objects have beendetected, they are classified using a classic supervised learningapproach, based on the Haar-like feature Cascade classification (asdescribed in P. A. Viola, M. J. Jones: Robust Real-Time Face Detection.ICCV 2001).

According to embodiments, the system is trained and tested, and thealgorithms run only on moving objects, thereby reducing thepossibilities and variety of the training, and input sets of images. Inshort the classification scheme only needs to recognize moving urbanobjects from each other, as opposed to recognizing one type of objectfrom any other possible matrix of pixels.

A tracking layer detects the trajectory of one given object over time.The system uses a novel approach based on a holistic model of thetrajectories in the image based on existing known foreground objects ornewly emerged objects.

An analysis layer uses the type and trajectory information to detecthigher level, human readable data such as vehicle or pedestrian speed,and people entering or exiting a location. Inferences can also be drawnbased on building layouts, vehicle traffic flows, and pedestrian trafficflows.

Data Algorithms: Line Analysis

Embodiments also include data algorithms that perform specific tasksbased on the data obtained from the main stack of video algorithmsabove. As an example of a data algorithm, line analysis will bedescribed in detail below.

Line analysis is a data algorithm that uses a video of a line to detecthow many people wait in line and how long it takes them to go throughthe whole line. Embodiments analyze a waiting line in real time videosequences. The goal of the algorithm is the estimation of lineattributes in real time that can be useful for somebody in the processof deciding whether to join the line. For example, estimations for thenumber of people that currently wait in the line and for the currentwait time are extracted. The current wait time is an approximation ofthe time that a person will have to wait in the line if she joins it inthis moment. With reference to FIG. 2, the analysis has three processesthat are repeated to every new captured video frame: 1) detection ofactivity areas, 2) waiting line segmentation; and 3) measurement ofattributes.

With reference to FIG. 3, the first step detects those areas in thevideo sequence that have potential human activity. This step is doneusing the previously described moving foreground detection. The currentframe is the input being run through the process (1.1) movementdetection and process (1.2) foreground detection. The output of thoseprocesses in one instance are combined creating an activity mask and arerun through the (1.1) contour extraction process. The output of this isthe activity contours, which essentially model a waiting line from theinput video data. The output of process (1.1) and (1.2) in anotherinstance is run through the process (1.3) update background model. Theexpected background is generated and that is passed back through process(1.2) foreground detection.

Process (1.1) works specifically by starting with the current frameinput. The current frame input is run through a non-linear time-domainhigh-pass filter which contains processes Ẑ(−1), absolute difference andbinary threshold. After being run through the non-linear time-domainhigh-pass filter R, G, B planes with saturation are added. The output ofthis is run through the space-domain median filter. Once filtered theoutput is run through either of two routes. In one instance the outputis run through a non-linear time-domain low-pass filter which does atime-domain low-pass filter and binary threshold. After running throughthe filter a copy with the mask is made and the binary threshold isfound. The output of this is considered a high activity area and isadded to the low activity areas produced by the other instance. In theother instance the output from the space-domain filter has the colorsinverted and noisy frames rejected before running through the samelinear time-domain low-pass filter described above. The output of thisis the low-activity areas. The low-activity area is subtracted from thehigh activity area to return the area with movement.

Process (1.2) starts with the inputs current frame and expectedbackground. The absolute difference of the current frame and theexpected background is found and then R, G, B planes with saturation areadded. The absolute difference is then merged with Background (MADB) andthe binary threshold of that is found.

Process (1.3) works specifically by starting with an activity mask asthe input. The activity mask is sent through an opening process and thenthe mask is expanded. The MAM is introduced to the output of thatprocess and the mask areas where background does not change are sent tobe copied and combined with the expected background. After the MAM isintroduced the process will also invert the mask and take the areaswhere the background does change to make a copy of the current frameusing these mask areas. It also will take as copy of that mask andcombine it with the expected background. The weighed sum of these copiesis found and combined with the masked copy of unchanged background.

Process (1.4) contour extraction starts with the input activity mask. Anopening is applied on the activity mask and the output is run throughthe TC89 algorithm to return the activity contours.

With reference to FIG. 4, the second stage infers which areas from thefirst step actually conform to the waiting line, rejecting any othersurrounding activity. The waiting line segmentation finds the activitycontours from the previous block and determines which of them actuallybelong to the waiting line. The algorithm needs a manually-defined areawhere to look for the line head. The line head is at the point towardswhich people in the line are waiting to access and is composed by thepeople that are about to access. If such line head is found, the rest ofthe line's first segment is found by fitting a curve model. Then, if theline has discontinuities due to the gaps between the people or occludingobjects, any other potential line fragments are sought and included inthe model. Finally, a longer-term line model is updated with the linefound in the current frame, in case that the observation is not toonoisy.

There can be situations in which the image of the waiting line has gaps.This can be due to people standing too far from each other or becausethe line passes behind occluding objects, like trees or light poles. Tocope with these situations, contours that lay after the liners firstcontour end point are sought. If they meet the certain conditions, theyare appended to the line's tail, the end point is updated and the searchprocess is repeated until no more potential line contours are found.

Referring to FIG. 4 in more detail, the process of waiting linesegmentation starts with the activity contours as input. Then theoperation (2.1) find line first contour is completed producing an inputthat is run through the operation (2.2) find optimal path from startpoint over contour. The output of this operation is run throughoperation (2.3) to extend path from end point of first contour overfragmented contours. The output of (2.3) is run through the operation(2.4) update line model which creates two outputs being the curve modelof line and the line contours.

The operation (2.1) find line first contour starts with the inputactivity contours. The activity contours are run through the operationto find contours that touch the user-defined line start box. The outputof the operation is then sorted to find the one with the largest area.The output from this is the line first contour.

The operation (2.2) find optimal path from start point over contour usesthe input line first contour. The line first contour is processed toextract the contour curvature. The output of this is run through alow-pass filter curvature. After the filter the curvature local maximais found. The output results then provide the path over the contourbetween start point and a local maxima that maximizes the benefit scoreB. The output of this process is the optimal carve model.

The operation (2.3) extend path from end point of first contour overfragmented contours operates by taking the optimal curve model as aninput. The end point of the optimal curve model is then found. Then thederivative at local interval around optimal curve end point is found.The next operation is the initialization step for an iterative process,where the current line first contour is stored in S, all other contoursare stored in R, and the curve end point is added as the first elementof the path set P, this first element is represented by assigningsubscript index i to zero. The iterative process will go through allcontour elements N in R that are close to the current line first contourS and do not imply a subtle turn, these two decisions are made alsobased on the input threshold maps. Threshold maps are also an input atthis part of the process. The output is then analyzed for two outcomes:if size of N=0 then the extended path (P) has been found; and if size ofN=0 is not true then S=N, remove N from R. This process recalculates theaverage of all elements in N of the element's farthest point from thecurrent optimal curve end point. The derivative is then updated withthis estimated average. The current optimal curve end point then equalsthe point of contour in N whose projection is highest over thederivative. The output of this process then added to the extended pathP, then iteration of the calculation of N using threshold maps takesplace.

The operation (2.4) update line model starts with the input extendedpath (P). The path is subsampled to a fixed number of points. Subsamplesare used to find the total length of the extended path (P) which issubtracted from its inverse, yielding a delta L which is input to aGaussian estimator and that is used for normalization.

If normalized delta L is determined to be too high, then the curve modelof the line has been found. If normalized delta L is not determined tobe too high, the line model is updated with P before outputting thecurve model of the line.

With reference to FIG. 5 and FIG. 6, the third step estimates the lineattributes of interest. There are currently two attributes that can bemeasured for a waiting line: the number of people in the line and theaverage wait time. The number of people is estimated from the linelength with a heuristic people density function. The wait time isinferred from the line length and an estimation of the average linespeed.

The estimation of the number of people that wait in the line is the lineintegral along the line model of a people density function. Since thedensity function variable is a distance over the ground plane, atransformation from image pixels to ground plane distance units must beapplied first. The trans formation is pre-computed for the specificcamera intrinsic and extrinsic parameters. The density function isnumerically integrated and, therefore, a first super-sampling step isrequired to ensure proper accuracy of the result.

In low quality video footage, it is sometimes impossible to distinguishindividual people, so tracking waiting persons to know the time that ittakes to travel the whole line is usually not viable. Instead, thisapproach to estimating the average wait time consists in dividing theline length by the average line speed. The line speed is estimated bycomputing the optical flow of a set of salient points into the linecontours over each pair of consecutive frames.

The salient points are found by running the Shi-Tomasi corner detector[1] over the line contour areas. The optical flow is computed with apyramidal version of the Lucas-Kanade algorithm [2]. Noisy flowvectors—those with impossible speeds for a person walking in a line—areremoved from the resulting set. When dividing the line length by theaverage speed, the resulting wait time is a number of frames. Thisfigure depends on the camera frame rate. The conversion to seconds isachieved by dividing the result by the camera frame rate. Since thesystem has to deal with variable frame rate video streams, there is aframe rate estimator block that provides this measure.

Referring to FIG. 5 in more detail, some of the many attributes that canbe estimated include 3.1 an estimate of the number of people, and 3.2 anestimate of average wait time. To estimate the number of people, thecurve model of line is super-sampled and the output lengths aresegmented in pixels to real ground units using a camera-to-ground-planetransform. The density of people function is integrated over the realline, yielding the estimate of the number of people.

Referring to 3.2, the average wait time is estimated by transforming theline contours and picking contours for shortest length model, also usinga transform of the curve model of the line. Mask contours are generatedfrom the contours. Then a copy with the mask (using the current frame)is used to find Shi-Tomasi features in this masked frame. Also, a aninversed transformed copy with the mask (using the transformed currentframe) is used to find Shi-Tomasi features the Shi-Tomasi features inthe second copy. Shi-Tomasi features from both copies are inputs to theLucas-Kanade Pyramidal optical flow the input is provided to computeflow vectors. Then noisy flow vectors are filtered out and resultingvectors are projected over the line model.

Using a camera-to-ground-plane transformation, then the camera vectorsare transformed to ground vectors and averaged, yielding a line speedestimate which is filtered for line speed outliers both with and withoutbeing run through a Gaussian estimator. The filtered line speed is runthrough the time-domain low-pass filter to obtain average wait frames(line_length divided, by line_speed). The average wait frames are thenfiltered and converted from frames to seconds using a wait frameestimator, to yield an average wait (TUAN COMMENT: do we need todescribe FIG. 6?).

FIG. 7 is shows a user interface display with a waiting line as capturedby a video camera with currently calculated attributes imposed on theimage.

Additional Data Algorithms

Automated Detection of Building Entrances Using Trajectories: AreasWhere Many Trajectories Start or End are Likely to be BuildingEntrances.

The recognition and tracking algorithms described above are able todetect, recognize and track the trajectories of pedestrians, vehicles,and other types of urban elements. Based on the output of thisalgorithm, we are able to detect starting points and ending points ofpeople or vehicles. We can detect areas of the video streams where morepeople or vehicles start or end their trajectories over long periods oftime—typically 24 hours are required. These areas, when not on theborder of the video streams, are areas where these elements appear ordisappear.

Some of these areas will be areas of occlusion—a tree canopy, a largeobject hiding the view, etc. In such cases there are clear borders tothe start and end points of trajectories and no trajectory will start orend, at all, where the occlusion is.

In cases where trajectories appear or disappear in a more scattered anddistributed way, we probably are seeing a building entrance.

In order to automatically detect building entrances or exits, werepresent all starting or ending points of trajectories on a map of thevideo stream. Then we run as local window analysis of the geographicdistribution of these points. We can either use moments or simply crosspoint distance, or even principal components analysis. Moments anddistances have proven to be great indicators of building entrances. Thisis extremely valuable to detect building automatically but also to startcounting people coming in and out. Every trajectory starting in thatentrance area will count as one person exiting the building. Everytrajectory ending there will count as a person entering the building. Bycounting these entrances and exits continuously, statisticallycorrecting numbers for detection errors, we can get to a real time countof occupancy and traffic in a given location. This is valid for people,cars, any type of vehicles.

Automated Segmentation of Urban Scenes: By Analyzing Where, an Average,Male or Vehicles or Bicycles are Located in an Image We CanAutomatically Detect Where Sidewalks, Roads, Bike Routes and RoadCrossings are.

Using the same algorithms as the ones described above, we havetrajectory information about different types of elements of urbanscenes. For this data analysis, the focus is on pedestrian, vehicles,public transportation vehicles, bicycles. By adding up all trajectoriesin a map of the video feed (pixels corresponding to the video feedpixels) we can have a map of where each type of elements moves and is inthe image. If it is pedestrians, these areas will be mostly sidewalks,crossroads, parks, plazas. If it is vehicles, it will be roads. Forbicycles it will be bicycle lanes. If both vehicles and pedestrians aredetected at non overlapping times, this will he crosswalks. This mapwill be quite accurate even if the detection and classification ofobjects is not very accurate. Embodiments typically work with detectorsthat have a <10% false positives rate and >50% detection rate.

Using this approach a map of the image is automatically built up, thusimproving classification results. A post process detection scores can beposted based on this map—a pedestrian detection score in a sidewalk areawill be increased, decreased in non-classified areas (buildings, sky,etc). Or the algorithm parameters can be adjusted based on imagelocation—a prior optimization approach as opposed to the posteriorapproach described right before.

“Virtual Turnstile” Approach: Counting How Many People Cross a LineDrawn on a Video.

In this data analysis, groups are considered. The algorithmself-calibrates in a first step, assessing the average dimension of aperson. To do this it registers all the sizes of moving objects crossingthe threshold. It assumes they are mostly people. It also assumes thatat least a given percentage N of them are not merged into groups. If weorder all sizes, the N*tot_elements/100 element represents the typicalperson's size. This is used to inter how many people are in a blob thatcrosses the line. We assume that there is always a certain overlapbetween people and factor that into the regression function to an fromnumber of pixels in the blob to # persons in the blob. Alternatively, aground truth approach is used to adjust parameters and have as linearper part regression function: we design a liner-per-part model (a set ofconnected segments) as the function f(x)=n where x is the # pixels and athe estimated number of people. A linear regression is used to start,and then the set into two subsets where the samples are divided by two,and iterate until reaching the desired number of segments—typically 8.

This methodology was tested on views of the 9-11 Memorial Park in NYCcaptured by one smart phone camera, as shown in FIG. 8. Accuracies up to98% were under normal conditions. Under average conditions accuracyreaches 86%.

Aspects of the systems and methods described herein may he implementedas functionality programmed into any of a variety of circuitry,including programmable logic devices (PLDs), such as field programmablegate arrays (FPGAs), programmable array logic (PAL) devices,electrically programmable logic and memory devices and standardcell-based devices, as well as application specific integrated circuits(ASICs). Some other possibilities for implementing aspects of the systeminclude: microcontrollers with memory (such as electronically erasableprogrammable, read only memory (EEPROM)), embedded microprocessors,firmware, software, etc. Furthermore, aspects of the system may heembodied in microprocessors having software-based circuit emulation,discrete logic (sequential and combinatorial), custom devices, fuzzy(neural) logic, quantum devices, and hybrids of any of the above devicetypes. Of course the underlying device technologies may be provided in avariety of component types, e.g., metal-oxide semiconductor field-effecttransistor (MOSFET) technologies like complementary metal-oxidesemiconductor (CMOS), bipolar technologies like emitter-coupled logic(ECL), polymer technologies (e.g., silicon-conjugated polymer andmetal-conjugated polymer-metal structures), mixed analog and digital,etc.

It should be noted that the various functions or processes disclosedherein may be described as data and/or instructions embodied in variouscomputer-readable media, in terms of their behavioral, registertransfer, logic component, transistor, layout geometries, and/or othercharacteristics. Computer-readable media in which such formatted dataand/or instructions may be embodied include, but are not limited to,non-volatile storage media in various forms (e.g., optical, magnetic orsemiconductor storage media) and carrier waves that may be used totransfer such formatted data and/or instructions through wireless,optical, or wired signaling media or any combination thereof. Examplesof transfers of such formatted data and/or instructions by carrier wavesinclude, but are not limited to, transfers (uploads, downloads, e-mail,etc.) over the interact and/or other computer networks via one or moredata transfer protocols (e.g., HTTP, FTP, SMTP, etc.). When receivedwithin a computer system via one or more computer-readable media, suchdata and/or instruction-based expressions of components and/or processesunder the system described may be processed by a processing entity(e.g., one or more processors) within the computer system in conjunctionwith execution of one or more other computer programs.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense as opposed to anexclusive or exhaustive sense; that is to say, in a sense of “including,but not limited to.” Words using the singular or plural number alsoinclude the plural or singular number respectively. Additionally, thewords “herein,” “hereunder,” “above,” “below,” and words of similarimport refer to this application as a whole and not to any particularportions of this application. When the word “or” is used in reference toa list of two or more items, that word covers all of the followinginterpretations of the word: any of the items in the list, all of theitems in the list and any combination of the items in the list.

The above description of illustrated embodiments of the systems andmethods is not intended to be exhaustive or to limit the systems andmethods to the precise forms disclosed. While specific embodiments of,and examples for, the systems components and methods are describedherein for illustrative purposes, various equivalent modifications arepossible within the scope of the systems, components and methods, asthose skilled in the relevant art will recognize. The teachings of thesystems and methods provided herein can he applied to other processingsystems and methods, not only for the systems and methods describedabove.

The elements and acts of the various embodiments described above can becombined to provide further embodiments. These and other changes can bemade to the systems and methods in light of the above detaileddescription.

In general, in the following claims, the terms used should not beconstrued to limit the systems and methods to the specific embodimentsdisclosed in the specification and the claims, but should be construedto include all processing systems that operate under the claims.Accordingly, the systems and methods are not limited by the disclosure,but instead the scope of the systems and methods is to be determinedentirely by the claims.

While certain aspects of the systems and methods are presented below incertain claim forms, the inventors contemplate the various aspects ofthe systems and methods in any number of claim forms. For example, whileonly one aspect of the systems and methods may be recited as embodied inmachine-readable medium, other aspects may likewise be embodied inmachine-readable medium. Accordingly, the inventors reserve the right toadd additional claims after filing the application to pursue suchadditional claim forms for other aspects of the systems and methods.

What is claimed is:
 1. A system for activity monitoring using videodata, the system comprising: at least one special purpose processorexecuting a plurality of video analysis worker processes; a managementsubsystem coupled to the at least one special purpose processor; and asplurality of video data sources of multiple types producing video dataof different types, wherein the plurality of video data sourcescomprises at least one mobile device executing a video sensingapplication that produces a video stream for processing by the videoanalysis worker processes.
 2. The system of claim 1, wherein themanagement subsystem comprises: a feed management subsystem for managingvideo data from the plurality of video data sources; is workermanagement subsystem for managing the video analysis worker processes; alocation management subsystem for managing geographic informationrelated to the plurality of video sources; and a data storage subsystemfor managing storage of data including unprocessed and processed videodata.
 3. The system of claim 1, further comprising a user interfacecoupled to receive video data from the data storage subsystem and topresent the video data in a human-accessible manner.
 4. The system ofclaim 1, further comprising a contributor management subsystem formanaging entities that control the plurality of video data sources,wherein entities comprise individuals, companies and organizations. 5.The system of claim 1, wherein the video analysis worker processescomprise a process for detection of activity areas.
 6. The system ofclaim 5, wherein the process for detection of activity areas comprises:detecting movement in a current video frame; detecting foreground in acurrent video frame; and generating and updating a background model togenerate and expected background.
 7. The system of claim 6, wherein thevideo analysis worker processes comprise a process for detection ofactivity areas results in activity contours to model a waiting line fromthe video data.
 8. The system of claim 7, wherein the activity contoursare operated on to generate a curve model of the waiting line and linecontours.
 9. The system of claim 8, wherein the curve model and the linecontours are operated on to measure attributes of the waiting line inreal time.
 10. The system of claim 9, wherein the attributes comprise anumber of people in the waiting line, and an average wait time.
 11. Acomputer implemented video data processing method, comprising: asplurality of special purpose video analysis processors receiving aplurality of video data streams from multiple sources of different typesin different locations that generate different types of video datastreams; the plurality of special purpose video analysis processorsexecuting a plurality of video analysis worker processes that operate onthe video data streams to generate processed video data that includesreal time information related to scenes; and executing as video sensorapplication on a mobile device which is one of the multiple sources,wherein the video sensor application performs various functions usingthe mobile device, the functions comprising, encoding consecutive videofiles; time stamping the consecutive video files; and pushing theconsecutive video files to a file server to produce a stable stream ofvideo data.
 12. The method of claim 11, further comprising the videoanalysis worker processes unifying geo location and time referenceinformation from the plurality of video data streams such that processedvideo data having similar geolocation and time reference informationgenerated from the multiple sources can be compared.
 13. The method ofclaim 11, further comprising the video analysis worker processes:gathering and storing processed data from the plurality of videostreams; architecturally removing any dependency of the special purposevideo analysis processors on the different types of video data streams;merging the video data from the multiple sources; and packaging andserving processed data as an output.
 14. The method of claim 11, whereinthe video analysis worker processes are accessible via a plurality ofapplication programming interfaces such that the video analysis workerprocesses instantiated on and executable on a plurality of operatingsystems, wherein the operating systems comprise Linux, Mac OS, andWindows.
 15. The method of claim 14, wherein the video analysis workerprocesses report level of central processing unit (CPU) activity,availability, and data storage capacity.
 16. A computer-readable mediumhaving instructions stored thereon, that when executed by a processorcause a video processing method to be performed, the method comprising:executing a plurality of video analysis worker processes that operate ona plurality of video data streams to generate processed video data thatincludes real time information related to scenes, wherein the multiplevideo streams originate from a plurality of devices of different types,wherein the video analysis worker processes, detect moving objects basedon estimating a background image of a fixed video stream; classify themoving objects as one of “known object” and “noise; and track atrajectory of one object over time.
 17. The computer-readable medium ofclaim 16, wherein the method further comprises the video analysis workerprocesses operate on only moving object video data to detect humanreadable data comprising vehicle speed, pedestrian speed, humansentering a location, and humans exiting a location.
 18. Thecomputer-readable medium of claim 16, wherein the method furthercomprises the video analysis worker processes: gathering and storingprocessed data from the plurality of video streams; architecturallyremoving any dependency of the processors on the different types ofvideo data streams; merging the video data from the plurality ofdevices; and packaging and serving processed data as an output.
 19. Thecomputer-readable medium of claim 16, wherein the method furthercomprises executing a video sensor application on a mobile device whichis one of the plurality of devices, wherein the video sensor applicationperforms various functions using the mobile device, the functionscomprising, encoding consecutive video files; time stamping theconsecutive video files; and pushing the consecutive video files to afile server to produce a stable stream of video data.
 20. Thecomputer-readable medium of claim 16, wherein the method furthercomprises the video analysis worker processes make the processed dataavailable to one or more user interfaces that display graphicalinformation and text information regarding a scene in real time.